Elevator counterweight guide clamp safety



Oct. 4, 1955 c. R. CALLAWAY ELEVATOR COUNTERWEIGHT GUIDE CLAMP SAFETY 5Sheets-Sheet l Filed Nov. 20, 1952 w K r as w TA N m P m m N o T 7 lv wL4,,

cuv.

Oct. 4, 1955 c. R. CALLAWAY ELEVATOR COUNTERWEIGHT GUIDE CLAMP SAFETY 5Sheets-Sheei 2 Fiigd Nov. 20, 1952 emx m EI

0 w& 8

Q? INVENTORF f C LARENCE. R. CALLAWAy. omusgv By Lmmw CALLAWAYIExEeu-rmx By HT'TOENEY /riL Oct. 4, 1955 c. R. CALLAWAY ELEVATORCOUNTERWEIGHT GUIDE CLAMP SAFETY 5 Sheets-Sheet 3 Filed Nov. 20, 1952INVENTOR. CLARNCE R. CALLAWAY, Dscnszo By L.\L\-IAN CALLAWAY.Exicp-rfilx HTTOEA/EV 4, 1955 c. R. CALLAWAY 2,719,608

ELEVATOR COUNTERWEIGHT GUIDE CLAMP SAFETY CLARENCE. R. CALLAWAY, DscuszuayLuu/w CALLAWAY, ExEcuTmX M LSQWLW ATTOEA/E) C. R. CALLAWAY ELEVATORCOUNTERWEIGHT GUIDE CLAMP SAFETY Oct. 4, 1955 5 Sheets-Sheet 5 FiledNov. 20, 1952 INVENTOR.

mm H AQ N ET P u .1 7 WI on MY MM m saw Wu United States Patent OfiiceELEVATOR COUNTERWEIGHT GUIDE CLAMP SAFETY Clarence R. Caliaway,deceased, late of Fort Myers, Fla.,

by Lillian Callaway, executrix, Fort Myers, Fla., ass'ignor'to WatsonElevator Company, Inc., New York, N. Y., a corporation of New YorkApplication November 20, 1952, Serial No. 321,660 9 Claims. 01. 187-30This invention relates to elevator counterweight. guide clamp safeties,and more particularly to an improved flexible guide clamp safety for anelevator counterweight.

In copending application .of Clarence R. Callaway, Serial No. 313551,filed October 7,jl9 52,there is shown an improved elevator car flexibleguide clamp safety in which the elevatorcar is brought to an emergencystop by applying braking action upon the guide rails in the event theelevator exceeds a predetermind sped of downward movement. This preventsan elevator from dropping if the cables suspending the elevator shouldpart for any reason.

Elevator cars are fitted with counterweights to balance the weight ofthe car. If the counterweight suspension cable should part by accidentalmeans, the counterweight would 'be allowed to drop. Frequently elevatorsare installed in tall buildings such that the elevator shaft is locatedabove an occupied space or area. Unless some means .are provided forbraking .free descent of acounterweight there exists serious danger thatthe counterweight will crash through .the .bottom of the elevator shaftinto the occupied area and cause damage to lifeand property.

The flexible guide clamp safety, as shown .in said .620- pendingapplication of Clarence R. Callaway, is-too bulky for installation as asafety for a counterweight which usually occupies a-restrictedcross-sectional area.

Safety devices for stopping counterweights in event of their excessivedownward speed :are known to .the .art.

These :devices usually take the form of .a spring=actuated brake adaptedto clamp the guide rails which serve to guide the counterweight. If theclamping pressure exercised by the spring is'too weak, the counterweightwill not be brought toastop; If the clamping pressure .is too great, theclamp may seize the guide rails, .and .if-the energy .is sufiicientlygreat, .carrythem away with attendantdamage to apparatusand injury topersons.

One object of this invention is to provide aflexible guide clamp safetyfor counterweights for elevatorcars in :which heavy spring pressuremaybe employed and yet insure that the icounterweight brought to-a-stop;in sucha gradiual manner as to avoid injury either-topersons orproperty. I

Another .object iofithis invention ,is to .provide la flexible guide:clamp safety for eounterweights whichimay The :installed'withinareduced cross-sectional area.

A furtherobject of this'invention .isto provide a=flexi- Figure 2.

Patented Oct. 4, 1955 A further object of this invention is to provide acounterwei ght flexible guide clamp safety 'having clamping jaws whichwill align themselves correctly with the guide rails at all 'timesindependent of imperfections in the guide rails. In general thisinv'ention contemplates the provision of a pair of jaw -levers biased toa fixed position by a stout spring. The spring acts against the stop andthere 'isnorma'lly -no pressure against the clamping jaws. Adjacent theguide -r'ails there 'is positioned a pair of wedgeshaped clamping jawsadapted to be moved into engagernent with the guide rails when it isdesired to brake the counterweight. Between 'eac'h pair comprising oneof the jaw levers and one-ofthe wedge-shaped jaws there is providedaplurality of balls disposed in a'ball carrier. Means tofpos'ition theball carrier correctly with respect to the jaws in all positions isprovided. The wedging action between the guide rails and the jaw leverstends to cam the ends of the jaw levers inwardly, that is, toward eachother. This motion will cam a thrust-transmitting 'carn member-againstthe action of the spring, the thrust being transmitted through theballs. The arrangement is such that when the clamping jaws have reachedtheir limit of motion a constant retarding force will be exercised uponthegu'id'e rails by the springswh'ich bias the cams which earn the jawlevers. The balls will insure that the wedgeshaped clamping jawsalwaysalign themselves properly with the surfaces of the guide rails since thethrust is being transmitted through spherical surfaces.

In the accompanyingdrawings which form part of the instant specificationand which are to be read in conjunction therewith and in-whichlikereference numerals are used to indicate like parts in the'various views:

Figure 1 is "an elevation of a counterweight mounted Lon a pair of'guiderails equipped with a 'flex'ible guide show the construction.

Figure '3 is a side 'elevation'ta'ken along the line 3-3 of Figure '4 isa sectional view drawn on'an'enlariged" scale taken along the line 4+4of Figure 2.

Figure 5 is-a sectional view drawn'on an enlarged'scale taken along theline 5-5 of'Figure 2.

Figure '6 is-a sectional vie Figure 7 is a sectional perspective viewviewed generally along the line 7 7 of Figure 2 with partsbroken awayand parts in section. I

, 'Figure8 is a sectional view drawn on an enlarged scale taken alongthe line"8-"8 of Figure 1.

More particularly, referring now 'to the drawings, the counterweightindicated generally by the reference numeral 10 is suspended fromca'bles12 secured to a coun- 'terweight frame 14 by means of 'a bracket16. The

Me guide clamp safety :for elevator connterweights by a frame 22 Whlch18 secured to the bottomof which a constant retarding :force will beappliedeven though the counterweight is traveling at high speed.

Another object ofthis invention is to provide axflexible guideclampsafety forcounterweights-which insures -the alignmentof the 'clampingjaws with the guide rails at all times.

to'a sudden'stopw'ith its attendant danger.

counterweight frame 14 is positioned between a pair of guide rails 18having a generally T-shaped cross-sectional "area. The counterweightframe 14 carries a plurality of weights 20. This guideclamp'safety-assembly 'is carried iwhich is governed by a governingdevice asis Well-known to the art. A tail rope 26 is attached to thegovernor rope by a-friction clamp (not shown). The arrangement is suchthat if the t counterweight moves downwardly at a speed in excess ofthat to which the governor is set,

there will 'bel-a tug #upon-the tail rope 26 in the direction drawn'onan enlarged scale takenalong the line 66 of Figure 2. i

of the arrows shown in Figure 1. The end of the tail rope 26 is securedto an arm 30 which is carried by a crank plate 32. This plate ispivotally mounted about a shaft 34 carried. by the counterweight-frame14. A lever 36 is pivotally carried by the frame 14 about shaft 38. Anadjustable link 40 connects one 'end of crank plate 32 to one end of thelever 36. The other end of lever 36 is connected by link 42 to ashiftable member 44 formed in the shape of a U having a pair of arms 54and 56. As can be seen by referenceto Figure 8,-the arm 54 of the member44 carries a flange 48. and the arm 56 of the member 44 carries a flange46. These flanges are positioned in a pair of guideways 50 and 52carried by the counterweight frame 14.

The frame 14 carries a bell crank 58 pivoted about a shaft 60. Anadjustable link 62 connects the crank plate 32 with the bell crank 58and a right-hand link 42 is connected to a right-hand shiftable member44 identical in construction to that shown in Figure 8 for the left-handshiftable member 44.

When there is a tug upon the tail rope 26, the right-hand end of arm 30will be pulled upwardly, rotating the crank plate 32 in acounterclockwise direction, as viewed in Figure 1. This will rotate thelever 36 in a clockwise direction and the bell crank 58 in acounterclockwise direction. The clockwise rotation of the lever 36 willpull the left-hand link 42 upwardly and the counterclockwise rotation ofthe bell crank 58 will pull the right-hand link 42 upwardly. Thus, anupward pull of the tail rope 26 will pull both shiftable members 44upwardly.

The lower portion of arm 54 of each shiftable member 44 carries a link70 pivoted thereto by a pin 72. Pivoted to each arm 56 by pin 74, a link76 is provided. The lower ends of these links'are attached to theclamping jaws which will be described more fully hereinafter.

Referring now to Figures 2 and 3, the guide clamp safety frame 22carries a pair of vertically positioned pins 80 around which arepivotally mounted a pair of clamping levers 82 and 84, there being onepair of clamping levers for each of the pins 80. Since the constructionis symmetrical for both guide rails 18, the construction with referenceto one of the clamping lever assemblies will be described. The lever 84is formed with a lever jaw 86 which is disposed to one side of theflange 17 of the guide rail 18 and spaced therefrom, as can readily beseen by reference to Figure 2. The lever 82 is provided with a lever jaw88 which is disposedon the opposite side of the flange 17 symmetricalwith the lever jaw 86. Each lever 82 and 84 is bifurcated, as canreadily be seen by reference to Figure 3. A disk 90 is positioned withinthe area formed by the lever arms. The disk carries a shaft 92 aroundwhich stout helical spring 94 is positioned. One end of the spring restsagainst the disk 90. A second disk 96 is provided with an aperture sothat it may pass over the shaft 92 to a position against the other endof the spring 94, as can readily be seen by reference to Figure 3.Secured to the disk 96 by bolts 98, a cam 100 is provided. This cam isadapted to coact with the lower bifurcations of the levers 82 and 84, aswill be pointed out more fully hereinafter. Similarly secured to thedisk 96 by bolts 102, an upper earn 104 for coaction with the upperbifurcations of the levers 82 and 84 is provided. The inner end of lever82 carries a pair of rollers 106 adapted to rotate about pins 108. Oneof the rollers is positioned on the upper bifurcation of lever 82, andthe other of the rollers is positioned on the lower bifurcation of lever82. Similarly, the inner end of lever 84 carries a pair of rollers 110mounted for rotation about pins 112. One of the rollers 110 is carriedby the upper bifurcation of lever 84 and the other of the rollers 110 iscarried by the lower bifurcation of lever 84. A plurality of spacerdisks 114 are positionedbetween the cam members 100 and 104 and the disk96 in order to enable the cams 184 and to be correctly positioned with aproper compression of spring 94. The

position of the cams is controlled by the nut 116 which is mounted onthe threaded end of shaft 92. The disk 96, the spacer members 114 andthe cams and 104 are adapted to slide as a unit upon the shaft 92.Securing the nut 116 upon the shaft compresses the spring and at thesame time moves the cams to the right, as viewed in Figures 2 and 3,against the action of the right-hand spring 94. This will permit theinner ends of the levers 84 and 82 to move inwardly, that is, toward thetransverse center line of the assembly. It will be observed that each ofthe cams 100 and 104 is provided with a pair of cam surfaces 118 and120. The cam surfaces 120 are adapted to coact with rollers 106, whilethe cam surfaces 118 are adapted to coact with rollers 110. If the nut116 is unscrewed on shaft 92 the spring 94 moves the cams to the left,as viewed in Figures 2 and 3, camming the inner ends of the levers 82and 84 outwardly, thus bringing the lever jaws 88 and 86 more closelyadjacent the flange 17. Since the nut 116 limits the action of thespring 94, the inner ends of the levers 82 and 84 will be free to moveoutwardly. A pair of stop members are provided to prevent this. A stopmember 122 is adapted to limit the outward position of the inner end oflever 84. The stop member 124 is adapted to limit the outward positionof the inner end of lever 82.

It will also be observed that the lever jaws 86 and 88 cannot be movedaway from the flange 17 without moving the inner ends of the levers 82and 84 inwardly. Such inward motion would cause the rollers 106 and 110,acting through the cam surfaces 120 and 118, to move the disc 96 to theright against the action of spring 94. In this manner, the jaws 88 and86 are spring loaded to take an outward thrust by a very compact springarrangement occupying a comparatively small cross-sectional area. Itwill also be observed that due to the fact that the length of the leverarm of each lever from its pivot pin 80 to the end of the lever jaw isshort with respect to the length of the lever arm from the pivot pin 80to the roller pins which carry the rollers. In this manner the force ofspring 94 is greatlymultiplied so that a'comparatively small spring willexercise a large thrust. The mechanical advantage of the levers can alsobemultiplied by the correct angle of the cam surfaces 118 and 120. Ifthe inclined surfaces extend 45 with respect to a vertical plane passingthrough the roller pins, no mechanical advantage is obtained. Bydisposing the cam surfaces at, a more obtuse angle than/15 with thisplane the mechanical advantage of the spring is increased, as will bewell'understood by those skilled in the art.

Referring now to Figure 4, the frame 22 below the lever and springassembly carries a stub shaft on one side of the flange 17 and a stubshaft 132 on the other side of flange 17; A bracket 134 is provided withtwo downwardly directed flanges 136 and 138. The flange 136 is providedwith a pin 138' around which a lever 140 is pivoted. Similarly, theflange 138 is provided with a pin 142 around which a lever 144 ispivoted. A link 146 is pivotally secured by pin 148 to the end of lever144. The other end of link 146 is pivotally connected to a wedge-shapedclamping jaw 1S0 disposed on one side of the flange 17. A secondclamping jaw 152 is disposed on the other side of the flange 17. Thisclamping jaw is connected by link 154 to the end of lever 140 by meansof'pin 156. The clamping jaw is connected at its upper end to the link76 and is supported thereby. The clamping jaw 152 is connected to thelower end of link 70 and is supported thereby. The stub shaft 130pivotally supportsa lever by pin to the other end of lever 144. Theother end of lever 158 is connected by pin 162 to a link 164 whichsupports a ball carrier 166 which is disposed between the leverv jaw 88and'the clamping jaw 150. The ball carrier supports a'plurality of balls168 through which thrust is adapted to be transmitted from the clampingjaw to the lever jaw. In a similar manner a lever170 is pivoted 158. Oneend of this lever is connected empress about stub shaft 132. neiend'ofthis -'l ever is connected by pin 172 to a link 174 which isconr'rectedto and supports a ball carrier 176%provided-with -balls 178, The otherend of lever 170 istzorrnectedfby pin 171*itio the otherendoflever140.(I w The construction can more clearly be seen by refer-- ence to Figure7. It will bezobservedthat the length'of the lever arm from stub shaft130 to pinaifll is twice :the length of the lever arm from "stub shaft130 10 :pin 162. The linkage is actuated, as pointed :out ab'ove, by theupward motion of the member whichzmoves link76 upwardly, thus moving thewedge shap'edlclamping Ejaw 150 upwardly. This motion'rotates-the lev'er144. Since the end of lever i144 is connected'lto the end ;of.lever'1'58 by pin 160, the lever 158 will'irotatesin the same .direc- Ition as lever 14'4. 'Theupward'rnotiomof link 164, however, will bethrough half the amplitude of the upward motion of link 148 due to the'iconstruetiomof the linkage. It will be observed that theclarnpingzjaw150 in the unclamped position shown in Figure 7 has its upper end aboutthe midpoint of the 'le'ver'ja'w 88. -It will also be observed that theupper portion of the ball carrier 166 is disposed about half way betweenthe top of the clamping jaw and the top of the'l'everjawffwhen the parts'are in clamping position, itis advantageoust hat the "leverj'aw, theball carrier and the wedge-shaped clamping jaw have their midpoints insubstantial alignment. To accomplish this, the ball carrier must travelthrough half the amplitude of the travel of the wedge-shaped clampingjaw. The linkage which has just been described accomplishes this. Whenthe links 70 and 76 pull the wedge-shaped clamping jaws 150 and 152upwardly half the distance traveled by the clamping jaws will betraversed by the ball carriers. The construction just describedmaintains the parts in their proper relationship and precludes slidingdisplacement of the ball carrier so that the thrust will be transmittedthrough all of the balls when the flexible guide clamp safety is in theclamping position.

In operation, when the elevator counterweight descends at a speed inexcess of that determined by the governor rope 24, the tug upon the tailrope will lift the arm 30 and rotate the crank plate 32 in acounterclockwise direction. This will rotate the lever 36 in a clockwisedirection and the bell crank 58 in a counterclockwise direction, thuslifting the members 44 through the links 42. This will lift bothwedge-shaped clamping jaws 150 and 152 upwardly through links 76 and 70.The upward motion of the clamping jaws 150 and 152 will lift the ballcarriers 166 and 176 upwardly together with their balls 168 and 178through half the distance which the clamping jaws travel, thus bringingthe clamping jaws and the ball carriers in horizontal alignment with thelever jaws 86 and 88. Due to the wedge-shaped configuration of both thelever jaws and the clamping jaws the clamping jaws will be cammedinwardly to grip the lateral surfaces of the flange 17 of the guide rail18. This, of course, will occur at both sides of the counterweight. Inthis motion the ends of the lever jaws will be moved outwardly, that is,away from each other. This motion will bring the inner ends of the leverjaws toward each other. Since the rollers 106 and 110, carried by thelever jaws, are in engagement with the inclined surfaces 120 and 118 ofthe cams 104 and 100, the inward motion of the inner ends of the levers82 and 84 can take place only by camming the cam members and theirsupporting disk 96 outwardly from the center of the assembly against theaction of the spring 94. Thus the clamping pressure upon the guide railflanges will be the spring pressure multiplied by the mechanicaladvantage of the cam and lever transmission. This spring pressure ismore than ample to bring the counterweight to a smooth stop. The brakingpressure will be substantially constant and there is no danger ofgripping the rails or of welding the wedge-shaped clamping blocks to theguide rail flanges. The spherical thrust surfaces afforded by the ballsin the ball carriers permit the alignment of the clamping jaws with theguide rail flanges and accommodate for any variations in the orientationof the guide rail flange 'surfaces along the guide rail. In this mannera constant predetermined clamping pressure is applied to provide aconstant retarding force which will bring the counterweight to a smooth'and rapid stop. The spherical bearing surfaces permit the jaws to alignthemselves at all times. The linkageconstraining the'ba'lllca rr iertotravel at half the speed of the clamping jaws insures the cor- -rectpositioning of the ball carriers and the clamping correct positioning ofthe 'ball carriers with'r'espect to the stationary lever jaws and -:themovable wedge-shaped jaws at all positions. Adequate-mesilient clampingpressureiis provided in a comparatively small cross-sectional area. Theclamping pressure can be readily adjusted by the initial compressionupon the springs by the use of the spacer plates between the cams andthe disk which carries them; All danger of seizing the rail by theclamping jaws and freezing them thereto is eliminated. The clamping jawscan be readily released by moving the arm 30 downwardly, thus pushingthe shiftable members 44 downwardly and constraining the clamping jawsto move downwardly away from the clamping position.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theappended claims. It is further obvious that various changes may be madein details within the scope of the claims without departing from thespirit of this invention. It is therefore to be understood that thisinvention is not to be limited to the specific details shown anddescribed.

This invention ,having been described, what is claimed is:

1. In an elevator counterweight guide clamp safety assembly, acounterweight, a guide rail for the counterweight, a frame carried bythe counterweight, a pair of levers carried by the frame pivotedintermediate their ends, a rod carried by the frame extending generallyin the same direction as the levers, a cam having a pair of cammingsurfaces carried by the rod for movement therealong, a spring positionedabout the rod having one end thereof abutting the frame and its otherend abutting the cam, one of said camming surfaces contacting the innerend of one of the levers and the other of the camming surfacescontacting the inner end of the other of said levers whereby. to cam theinner lever ends outwardly and the outer lever ends inwardly, meanscarried by the rod for limiting the movement of the cam axially thereof,the outer lever ends being disposed on opposite sides of the guide railand spaced therefrom, a bearing element carrier positioned between oneouter lever end and the guide rail, another bearing element carrierpositioned between the other outer lever end and the guide rail, bearingelements carried by the carriers, a clamping ,block positioned betweenone carrier and the guide rail,

another clamping block positioned between the other carrier and theguide rail, linkages connecting the respective carriers and clampingblocks and means responsive to a predetermined speed of descent of thecounterweight for lifting the clamping blocks whereby to clamp the guiderail therebetween, the construction being such that the clamping thrustwill move the outer ends of the levers 7 away from each other againstthe action of the spring.

2. An elevator counterweight guide clamp safety assembly as in claim 1,in which the outer lever ends are formed with surfaces which lie alongplanes diverging from each other in a downward direction, the bearingelements being adapted to engage said surfaces.

3. An elevator counterweight guide clamp safety assembly as in claim 1,in which the inner lever ends are provided with rollers, said rollersengaging the cannning surfaces.

4. An elevator counterweight guide clamp safety assembly as in claim 1,in which the bearing elements comprise balls.

5. An elevator counterweight guide clamp safety as sembly as in claim 1,in which said clamping blocks are wedge-shaped.

6. An elevator counterweight guide clamp safety assembly as in claim 1,in which each said linkage comprises a first lever pivoted intermediateits ends on said frame, a second lever pivoted intermediate its ends onsaid frame, means for pivotally connecting one pair of lever ends toeach other, means for connecting the other end of the first lever to aclamping block and means for connecting the other end of the secondlever to a carrier, the length of the lever arms being such that thecarrier will be moved through half the distance that a clamping block ismoved.

7. An elevator counterweight guide clamp safety assembly as in claim ,1,in which each of said pair of levers is bifurcated at its inner end.

87 An elevator counterweight guide clamp safety assembly as in claim 1,including means for varying the compression of said spring.

9. An elevator counterweight guide clamp safety assembly as in claim 1,in which said means responsive to a predetermined speed of descent ofthe counterweight for lifting the clamping blocks includes a tail rope,a lever pivotally carried by the counterweight frame intermediate itsends, means for securing the tail rope to one end of the lever, a secondlever pivoted on the counterweight frame intermediate its ends, a linkconnecting one end of the second lever with the other end of the firstlever and links connecting the other end of the second lever with theclamping blocks.

References Cited in the file of this patent UNITED STATES PATENTS

